scholarly journals Mass Cytometric Analysis Revealed Dynamic Alteration of the Tumor Immune Environment in Bone Marrow from Children with Recurrent B Cell Precursor Acute Lymphoblastic Leukemia

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2390-2390
Author(s):  
Takashi Mikami ◽  
Itaru Kato ◽  
James Badger Wing ◽  
Hiroo Ueno ◽  
Keiji Tasaka ◽  
...  

Abstract Introduction Due to the considerable success of cancer immunotherapy for leukemia, the tumor immune environment (TIE) has become a focus of intense research; however, there are few reports on the dynamics of the TIE in leukemia, especially in bone marrow (BM), the primary site of leukemia. Mass cytometry, which allows high-dimensional analysis with single-cell resolution, is a powerful tool for the characterization of the TIE, and enables us to examine pediatric BM samples containing only a few numbers of immune cells. Methods Primary and recurrent BM samples were collected serially from pediatric patients with BCP-ALL at Kyoto University Hospital from 2006 to 2013. Mononuclear cells were isolated by density centrifugation and viably preserved until they were used. We examined the TIE of pediatric B cell precursor acute lymphoblastic leukemia (BCP-ALL) by analyzing serial BM samples from patients in primary and recurrent disease phases by mass cytometry, using 39 immunophenotype markers, and transcriptome analysis. Results and Discussion The proportion of BCP-ALL cells in the samples was 87.3-97.8% (mean: 94.0%) at onset, and 81.3-98.8% (mean: 92.2%) at relapse. High-dimensional single-cell analysis by mass cytometry elucidated a dynamic shift of T cells from naïve to effector subsets, and clarified that the TIE during relapse comprised a T helper 1 (Th1)-polarized immune profile, together with the increase of effector regulatory T cells (Tregs). Th1 cells are typically known as supporters of cytotoxic T lymphocytes which would eliminate leukemia cells and work against relapse, but recently, it is reported that Th1 cells directly support ALL proliferation in vitro (Traxel et al. Oncogene. 2019; 38:2420-2431), and that the concentrations of pro-inflammatory cytokines and Th1 cytokines (IFN-γ and IL-12) were elevated in patients with ALL, which could create favorable conditions for ALL (Perez-Figueroa et al. Oncol Rep. 2016; 35: 2699-2706, Vilchis-Ordonez et al. Biomed Res Int. 2015; 2015: 386165). Therefore, there is a possibility that the Th1-polarized immune profile would work in favor of leukemia survival for relapse. Furthermore, Gene set enrichment analysis based on RNA expression identified the enrichment of six immune-related pathways were enriched at the time of relapse; chemokine activity, chemokine production, complement activation, positive regulation of cytokine production involved in immune response, positive regulation of lymphocyte chemotaxis, and positive regulation of lymphocyte migration. These expression signatures suggest that BCP-ALL cells attract lymphocytes, and upregulate immune activities at relapse. Conclusion In summary, a TIE characterized by a Th1-polarized immune profile, with the increase of effector Tregs, may be involved in the pathophysiology of recurrent ALL, and BCP-ALL cells at relapse were enriched with gene expressions related to lymphocyte attraction and activities. This information could contribute to the development of effective immunotherapeutic approaches against BCP-ALL relapse. Disclosures Ogawa: Eisai Co., Ltd.: Research Funding; Kan Research Laboratory, Inc.: Consultancy, Research Funding; Ashahi Genomics: Current holder of individual stocks in a privately-held company; Dainippon-Sumitomo Pharmaceutical, Inc.: Research Funding; Otsuka Pharmaceutical Co., Ltd.: Research Funding; ChordiaTherapeutics, Inc.: Consultancy, Research Funding.

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e21000-e21000
Author(s):  
A. Fauzdar ◽  
A. Mahajan ◽  
D. Jain ◽  
M. Mishra ◽  
V. Raina

e21000 Background: Chromosome abnormalities of leukemia cells have important prognostic significance in childhood acute lymphoblastic leukemia (ALL). B-cell precursor acute lymphoblastic leukemia (BCP-ALL) ETV6/RUNX1 (alias TEL/AML1) is most frequent i.e. 15 - 35% in the children with 2 - 18 age group. We report two new cases with Pre B- cell ALL without ETV6/RUNX1 rearrangement, showing amplification of AML1 gene detected by FISH analysis. Methods: Bone marrow samples were analyzed for chromosomal abnormalities with conventional G-banding techniques and interphase fluorescence in situ hybridization (FISH) using probes to detect BCR/ABL t(9;22)(q34-q11) fusion, cryptic TEL/AML1 t(12:21)(p13-q22) and MLL rearrangement for del 11q23. Results: In first case a 3-year girl with four copies of AML (RUNX1) gene were observed in 95% of the cell with normal two copies of TEL (ETV6) gene in both interphase and metaphase FISH. We observed BCR-ABL negative translocation and no MLL gene rearrangement in all the interphase cells after doing FISH. We got a normal 46XX karyotype from bone marrow with conventional cytogenetics (CC) in the same patient. In second case, a 4-year male we observed four copies of AML and two copies of TEL gene in more than 80% of cells. In this patient, we got BCR-ABL negative translocation and three copies of MLL gene without any rearrangement through FISH. We got normal 46XY karyotype in the same patient through CC. Conclusions: In both the patients, we observed hyperdiploidy detected with four copies of RUNX1 gene showing tetrasomy of chromosome 21 detected with metaphase FISH analysis whereas G-banding shows normal diploidy. Bone marrow karyotype in combination with molecular cytogenetic techniques like FISH should be done for improvement in sensitivity and accurate cytogenetic analysis in childhood ALL patients for proper identification of prognostic group for optimum treatment. This is one of the few reported studies worldwide for amplification of RUNX1 gene from Indian subcontinent in childhood BCP-ALL. No significant financial relationships to disclose.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1418-1418
Author(s):  
Nitin Jain ◽  
Audrey Lamb ◽  
Susan M. O'Brien ◽  
Farhad Ravandi ◽  
Marina Konopleva ◽  
...  

Abstract Background: Early T-cell precursor (ETP) acute lymphoblastic leukemia/lymphoma (ALL) is a recently recognized high-risk T-ALL subgroup. The optimal therapeutic approaches to adult patients with ETP-ALL are poorly characterized. In this study, we compared the outcomes of adults with ETP-ALL who received treatment on frontline regimens to those of patients with other T-ALL immunophenotypic subtypes. Methods: Patients with newly-diagnosed T-ALL who received frontline chemotherapy between the years 2000 and 2014 at The University of Texas MD Anderson Cancer Center (MDACC) were identified and immunophenotypically categorized into early, thymic, and mature per the European Group for the Immunologic Classification of Leukemia (EGIL)/WHO classification. Patients with ETP-ALL were identified on the basis of the following immunophenotype: CD1a(-), CD8(-), CD5(-/dim), and positivity for one or more stem cell or myeloid antigens. Patients received frontline treatment with the following chemotherapy regimens: hyper-CVAD alone (n=43), hyper-CVAD + nelarabine (n=44) or augmented BFM regimen (n=24). Results: A total of 111 patients with T-ALL with adequate immunophenotype data were identified. There was no difference in the outcomes of patients based on the EGIL/WHO subtypes (Fig 1). A total of 19 patients (17%) had ETP-ALL. The complete remission rate (CR)/CR with incomplete platelet recovery (CRp) rate in patients with ETP-ALL was significantly lower than that of non-ETP-ALL patients (73% vs. 91%; p=0.03). The median overall survival for patients with ETP-ALL was 20 months vs. not reached for the non-ETP-ALL patients (p = 0.008) (Fig 2). ETP-ALL remained a high-risk subgroup within the WHO 'Early' group (Fig 3). A subset of patients with early T-ALL had an immunophenotype that resembled that of ETP-ALL except for having ≥75% CD5 expression (ETP+CD5). The OS of patients with ETP+CD5 (n=19) was similar to that of non-ETP-ALL patients and differed from that of ETP-ALL patients (p=0.059). By univariate analysis, the following variables were significant for survival: age, WBC count (<50 vs. ≥50 x109 /L), platelet count (<100 vs. ≥100 x109 /L), LDH (<600 vs. ≥600 IU/L) and ETP-ALL (Table 1). By multivariate analysis, only age (HR: 2.862; 95%CI: 1.140-7.183; p=0.025) and ETP-ALL (HR: 2.275; 95%CI: 1.117-4.631; p=0.023) were significant. Conclusions: ETP-ALL represents a high-risk disease subtype of adult ALL. Allogeneic stem cell transplant in CR1 should be considered. Novel treatment strategies are needed to improve treatment outcomes in this T-ALL subset. Table 1. Univariate and multivariate analysis for survival Parameter Survival UVA MVA P P HR 95%CI Age ≥60 0.013 0.025 2.862 1.140-7.183 Gender 0.24 - - - Diagnosis (ALL vs. LBL) 0.13 - - - WBC < 50.0 (x 109 /L) 0.009 - - - Hemoglobin <10 (g/dL) 0.36 - - - Platelet <100 (x 109 /L) 0.036 - - - LDH <600 (IU/L) 0.045 - - - CNS involvement at Dx 0.18 - - - WHO classification (early, thymic, mature) 0.101 - - - ETP-ALL 0.008 0.023 2.275 1.117-4.631 Treatment received 0.43 - - - Figure 1. Overall survival of patients with T-ALL (N=111) categorized as Early, Thymic and Mature per EGIL/WHO Classification Figure 1. Overall survival of patients with T-ALL (N=111) categorized as Early, Thymic and Mature per EGIL/WHO Classification Figure 2. Overall survival of patients with ETP-ALL (N=19) compared to non-ETP ALL (N=92) Figure 2. Overall survival of patients with ETP-ALL (N=19) compared to non-ETP ALL (N=92) Figure 3. Overall survival of patients with WHO 'early' subcategorized as ETP vs. non-ETP, WHO 'thymic', and WHO 'mature' (N=111) Figure 3. Overall survival of patients with WHO 'early' subcategorized as ETP vs. non-ETP, WHO 'thymic', and WHO 'mature' (N=111) Disclosures Konopleva: Novartis: Research Funding; AbbVie: Research Funding; Stemline: Research Funding; Calithera: Research Funding; Threshold: Research Funding. Cortes:Astellas: Consultancy, Research Funding; BerGenBio AS: Research Funding; Novartis: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Ariad: Consultancy, Research Funding; Teva: Research Funding; Ambit: Consultancy, Research Funding; Arog: Research Funding; Celator: Research Funding; Jenssen: Consultancy.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3880-3880 ◽  
Author(s):  
Marc Schwartz ◽  
Lloyd E. Damon ◽  
Deepa Jeyakumar ◽  
Caitlin L. Costello ◽  
Dimitrios Tzachanis ◽  
...  

Clinical and preclinical findings suggest that PD-L1 overexpression on lymphoblasts and in the bone marrow microenvironment may mediate resistance to blinatumomab by inhibiting T-cell activation. We report preliminary findings from an ongoing phase I/II multicenter trial to evaluate the safety and efficacy of blinatumomab with pembrolizumab in adults with relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL) and a high bone marrow lymphoblast percentage (NCT 03160079). The primary objective of this Phase I/II trial is to determine overall response rate (ORR = complete response (CR) + complete response with partial hematologic recovery (CRh) rate) after 1-2 cycles of blinatumomab with pembrolizumab, with key secondary endpoints of adverse events (AEs), minimal residual disease (MRD)-negative CR/CRh rate, 2-year disease-free and overall survival, and allogeneic HCT rate. Eligible patients are 18 years of age or older with R/R B-ALL after ≥ 1 prior line of therapy (including Philadelphia chromosome positive (Ph+) B-ALL failing one second or third generation tyrosine kinase inhibitor) and >50% lymphoblasts on screening bone marrow sample. Patients receive blinatumomab by continuous IV at 9 mcg/day on days 1-7 and 28 mcg/day on days 8-28 of cycle 1, then 28 mcg/day on days 1-28 in subsequent cycles. Pembrolizumab 200 mg IV is given on days 15 and 36 of each 42-day cycle. Patients in CR/CRh after 1-2 cycles complete a maximum of 5 cycles. A safety cohort of up to 6 patients assessed safety by 3+3 design. Dose-limiting toxicities (DLTs) were defined as Grade 3 or 4 non-hematologic AEs related to the addition of pembrolizumab to blinatumomab with a DLT monitoring period of 28 days from the first pembrolizumab dose. At the time of this analysis, 5 patients have been enrolled and treated with all 5 completing the DLT monitoring period. Patients had a median age of 60 years (range 22-74) and one had Ph+ disease. Median bone marrow lymphoblast percentage at time of enrollment was 84% (range 53-90). Patients received a median of 1 cycle (range 1-3) of blinatumomab with pembrolizumab. Common AEs included fever, headache, increased bilirubin, nausea, neurotoxicity, and tachycardia. Grade 3-4 non-hematologic AEs included disseminated intravascular coagulation, hyperferritinemia, hypokalemia, subdural hematoma, encephalopathy, hyponatremia, and macrophage activation syndrome in 1 patient (all related to blinatumomab), hyperbilirubinemia and elevated AST in 1 patient, and hypertriglyceridemia in 1 patient. No grade 3 or greater immune-related AEs have occurred. No pembrolizumab-related DLTs occurred in the first 5 patients in the safety cohort and enrollment is now proceeding in the dose-expansion cohort. The ORR was 50% with 2/4 evaluable patients achieving a CR. One patient achieved an MRD-negative CR in cycle 1 and completed 3 cycles before proceeding to allogeneic HCT. One patient discontinued treatment due to subdural hemorrhage and macrophage activation syndrome during cycle 1 and achieved a CR. Both patients remain in CR for over 6 months. Two patients discontinued treatment due to refractory or progressive disease. The one patient not evaluable for response withdrew from study therapy after 1 cycle without ALL progression. Patient, disease, and treatment characteristics as well as outcomes are summarized in the Table. Blinatumomab with pembrolizumab is safe for adults with R/R B-ALL and a high bone marrow lymphoblast percentage. Enrollment continues in the dose-expansion cohort to assess efficacy. Disclosures Damon: Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Costello:Celgene: Consultancy, Honoraria, Research Funding; Janssen: Research Funding; Takeda: Honoraria, Research Funding. Schiller:Biomed Valley Discoveries: Research Funding; Astellas: Research Funding; Amgen: Other, Research Funding; Agios: Research Funding, Speakers Bureau; Bristol Myer Squibb: Research Funding; Celgene: Research Funding, Speakers Bureau; Constellation Pharmaceutical: Research Funding; Daiichi Sankyo: Research Funding; Eli Lilly and Company: Research Funding; FujiFilm: Research Funding; Genzyme: Research Funding; Gilead: Research Funding; Incyte: Research Funding; J&J: Research Funding; Jazz Pharmaceuticals: Honoraria, Research Funding; Karyopharm: Research Funding; Novartis: Research Funding; Onconova: Research Funding; Pfizer Pharmaceuticals: Equity Ownership, Research Funding; Sangamo Therapeutics: Research Funding. Wieduwilt:Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen, Leadiant, Merck, Servier: Research Funding; Reata Pharmaceuticals: Equity Ownership; Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Pembrolizumab (given off label)to enhance the efficacy of blinatumomab (given on label) for relaped/refractory B-cell acute lymphoblastic leukemia


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4952-4952
Author(s):  
Tomasz Szczepanski ◽  
Urszula Malek ◽  
Lukasz Sedek ◽  
Alicja Sonsala ◽  
Joanna Zawitkowska ◽  
...  

Abstract Background CXCR4 (CD184) is a receptor specific to the Stromal Derived Factor 1 (SDF-1), a ligand also known as CXCL12. The ligand-receptor interaction has a pleiotropic effect on hematopoietic cell proliferation, migration and activation through several signaling pathways. CXCR4 expression on neoplastic cells might be responsible for their dissemination to particular organs with cells expressing CXCL12 (e.g. lymph nodes, bones, and within bone marrow). In B-cell precursor acute lymphoblastic leukemia (BCP-ALL), expression of CXCR4 was associated with higher capacity of leukemic blasts to seed into bone marrow niches. Aim of the study The study aimed at thorough analysis of CXCR4 expression on BCP-ALL blasts and correlation of CXCR4 expression with the expression of other antigens such as CD66c, CD34, CD10, CD38, CD20 and CD45 as well as with the levels of minimal residual disease on day 15. Patients and Methods The study group consisted of 198 consecutive children aged 0-18 years (median 4.4 years) treated for BCP-ALL in the centers of the Polish Pediatric Leukemia/Lymphoma Study Group. Bone marrow samples obtained at initial diagnosis were stained with monoclonal antibodies (CD58, CD66c, CD34, CD19, CD10, CD38, CD20, CD45, CXCR4) in two 8-color tubes and analyzed with multiparameter flow cytometry (BD FACSCanto II, Becton Dickinson, San Jose, CA, USA) according to the EuroFlow standard protocols. The expression of particular antigens on BCP-ALL blasts was defined by median fluorescence. In 177 patients the samples from day 15 were available and analyzed for the presence of minimal residual disease (MRD) with multicolor flow cytometry. Infinicyt software (Cytognos, Salamanca, Spain) was used for more detailed analyses of the flow cytometric data. Results The expression of CXCR4 in BCP-ALL was highly variable with median fluorescence ranging from 252 to 24 388 (median 4011). There was no obvious correlation of CXCR4 expression with immunophenotype and with  the expression of other analyzed markers (CD66, CD34, CD10, CD38 i CD45). The only borderline significant correlation found was between CXCR4 and CD20 expression. On day 15, 70 children (39%) demonstrated MRD levels below 0.1%, which is consistent with MRD-based low-risk group. Among these patients, 41 children had undetectable MRD already at this time point. In contrary, MRD levels > 10% were recorded in 21 patients (12%), who were stratified to high-risk group, accordingly. Maximal MRD levels recorded at day 15 were 85.6%. In remaining 86 children (49%), MRD levels at day 15 were in-between 0.1% and 10%, which reflects intermediate response to the treatment. There was no correlation between CXCR4 expression and MRD levels at day 15. Conclusion CXCR4 expression on BCP-ALL blasts is highly heterogeneous and is not associated with particular leukemia immunophenotype. Further analyses should characterize clinical features of leukemia and treatment response with regard to CXCR4 expression. The study was supported by Polish National Center of Science grant N N407 687040. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5158-5158
Author(s):  
Anne S. Renteria ◽  
Sangeetha Venugopal ◽  
Bridget Marcellino ◽  
Alla Keyzner ◽  
Marina Kremyanskaya ◽  
...  

Abstract Background The outcomes of older adults with acute lymphoblastic leukemia (ALL) remain poor when compared to younger ALL patients [PMID 19897583, 28419558, 22409379, 10653870]. Asparaginase (Asp) induces death of human lymphoblasts, and effective asparagine depletion is associated with improved outcomes in ALL. PEG-Asparaginase (PEG-Asp), which has a longer half-life than Asp, is a key component of the intensive chemotherapeutic regimens utilized for treatment of pediatric and younger adult ALL [PMID 29450465]. Frequently, older patients with Ph-negative ALL are not offered PEG-Asp containing pediatric chemotherapy regimen because of concerns related to tolerability and safety in this population [PMID 28355969]. Methods The Adult Leukemia Program at Mount Sinai Hospital developed an age-based, dose-adjusted, CALGB 10403 based intensive chemotherapy regimen for adults (≥40 years) with a diagnosis of Ph-negative ALL. For patients up to 60 years, prednisone (PRD) dose was reduced from 60 to 40 mg/m2/day from D1 to D28, and PEG-Asp reduced from 2500 to 1000 units/m2 (D4). For patients aged 61 years and above, PRD was further reduced to 25 mg/m2/day, and PEG-Asp to 1000 units/m2 on D4. In CD20+ ALL, rituximab x 8 doses were added to the regimen. CNS-prophylaxis consisted of intrathecal methotrexate at D1, D8 and D29 during induction, and during subsequent courses of chemotherapy based on the CALGB 10403 protocol. A PEG-Asp oriented supportive care plan was developed to prevent and treat Asp-related adverse effects. After the administration of PEG-Asp, Antithrombin III (ATIII) and fibrinogen levels were monitored on the same day, twice a week, for at least two weeks. If ATIII levels were < 70% and/or fibrinogen levels < 120 mg/dL, levels were corrected with the administration of ATIII concentrate and/or cryoprecipitate, respectively. Results Twelve patients with a median age of 58 years (45 - 76) were evaluable, and three patients were ≥ 70 years. Nine patients had B-cell ALL and three T-cell ALL. Three patients had a white blood cell count > 30 x103/µL at diagnosis. An ECOG status ≤ 2 at diagnosis was described in all patients, and all of them had multiple complex cytogenetic and molecular abnormalities. Ten patients had significant co-morbidities at diagnosis, including diabetes, hypertension, previous history of cancer, coronary artery disease, obesity, alcohol related chronic pancreatitis, and chronic diarrhea. Nine out of the twelve patients (75%) attained a bone marrow morphological complete remission (CR) at the end of induction (EOI), three of them with detectable minimal residual disease (MRD) that became undetectable after completing course II. Of the three patients who had ≥5% bone marrow blasts at EOI, one attained a CR with undetectable MRD at the end of course IA and another when switched to blinatumomab, and the third one died of progressive disease. No patient experienced early death. Five patients underwent allogeneic hematopoietic stem cell transplantation (HCT) while in CR (age range 46 to 60 years) and four remain in CR at last follow up (median 489 days, range 181 - 841), and one died of relapsed disease 67 days post-HCT. The other six patients who are receiving chemotherapy are alive and in remission at last follow up (median 272 days, range 52 - 639). The common adverse effects associated with PEG-Asp administration in this older group of patients were asymptomatic hypofibrinogenemia and depleted ATIII levels requiring supplementation (n=8), severe hyperbilirubinemia (n=1), and non-life-threatening venous thrombosis (n=1). Severe allergic reaction, clinical pancreatitis and cognitive impairment were not observed. Conclusion This age-based dose-adjusted PEG-Asp containing regimen was associated with an encouraging CR rate and a tolerable and manageable adverse event profile in this older patient population with significant co-morbidities. Treatment related mortality was 0%. Ten of 12 patients are currently in sustained remission, either with chemotherapy alone or following allogeneic HCT (median follow up 422 days, range 52 to 841 days). Treatment optimization for older patients with ALL utilizing an intensified, age-adjusted PEG-Asp containing induction and consolidation therapy regimen is associated with favorable outcomes and provides an effective bridge to potentially curative therapies such as HCT. Further prospective evaluation is under way. Table. Table. Disclosures Kremyanskaya: Incyte: Research Funding. Mascarenhas:Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Promedior: Research Funding; Janssen: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Merck: Research Funding; CTI Biopharma: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding.


2006 ◽  
Vol 130 (2) ◽  
pp. 153-157 ◽  
Author(s):  
Loveleen C. Kang ◽  
Cherie H. Dunphy

Abstract Context.—MIC2 (“thymus leukemia”) antigen has been shown to be expressed by T cells and monocytes, as well as B cells and granulocyte-lineage cells. It is most intensely expressed by the most immature thymus T-lineage cells and is more intensely expressed by CD34-positive/CD33-positive myeloid cells (compared to more mature myeloid cells) and the earliest CD34-positive/CD10-positive B-cell precursor cells (compared to cells of later B-cell precursor stages). CD99 (MIC2) is characteristically expressed in precursor B- and T-cell lymphoblastic lymphomas/leukemias, as well as in Ewing sarcoma/primitive neuroectodermal tumors (ES/PNET). It has also been shown to be expressed in a few terminal deoxynucleotidyl transferase (TdT)–positive myeloid processes, but has been uniformly negative in TdT-negative myeloid processes. A more recent study showed that 43% of acute myeloid leukemias (AMLs) and 55% of chloromas express CD99, concluding that CD99 is commonly expressed in AML and rarely seen in myeloproliferative disorders, myelodysplastic syndromes, or normal bone marrow. Although this study speculated that MIC2 expression was probably not limited to TdT-positive AML, there was no comparison with TdT reactivity in this study. Objective.—Since AML and high-grade myelodysplastic syndrome may occasionally be difficult to distinguish morphologically from acute lymphoblastic leukemia and ES/ PNET, we undertook a study to analyze MIC2 expression in conjunction with TdT reactivity in distinguishing AML or high-grade myelodysplastic syndrome from acute lymphoblastic leukemia and ES/PNET. Design.—We studied bone marrow core and clot paraffin specimens from AML (classified according to criteria of the World Health Organization; n = 49), myelodysplastic syndromes (n = 4), precursor B-cell acute lymphoblastic leukemia (n = 4), ES/PNET (n = 1), and normal bone marrow (n = 3) with MIC2 (CD99) and TdT immunohistochemistry. Results.—Overall, CD99 was expressed in 24 (49%) of 49 AML cases, including all (11/11) TdT-positive cases. CD99 was expressed in all subtypes of AML except M5. Myelodysplastic syndromes and normal bone marrow specimens were uniformly CD99 negative. Expression of TdT was limited to a subset of AML-M0, -M1, -M2, and -M4, and AML with multilineage dysplasia. Conclusions.—In contrast to a previous study, CD99 expression was not restricted to TdT-positive hematologic proliferations. In particular, the CD99-positive M3 and M7 AMLs were TdT negative. An M5 AML may likely be excluded based on a uniform TdT-negative/CD99-negative immunophenotype. In addition, in our experience, CD99 should be routinely evaluated on bone marrow clots, owing to decreased reactivity or loss of reactivity in rapid decalcifying (RDO) solution–decalcified specimens.


Author(s):  
Gholamhossein Tamaddon ◽  
Mehran Bahraini ◽  
Alieh Fazeli

Background: Transcription factors (TFs) play a key role in the development, therapy, and relapse of B-cell malignancies, such as B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Given the essential function of Forkhead box protein P1 (FOXP1) transcription factor in the early development of B-cells, this study was designed to evaluate FOXP1 gene expression levels in pediatric BCP-ALL patients and NALM6 cell-line. Materials and Methods: This case-control study was done on the NALM6 cell-line and bone marrow specimens of 23 pediatric BCP-ALL patients (median age: 7.5 years; range: 2.0 – 15.0 years) at different clinical stages including new diagnosis, 15th day after the treatment, and relapse. Also, 10 healthy children were included as the control group. FOXP1 gene expression was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). The correlation analysis was performed between the FOXP1 gene expression and patients’ demographic and laboratory characteristics. Results: The results showed that FOXP1 gene expression was significantly downregulated in the NALM-6 cell-line (median=0.05, P<0.001) and patients at new diagnosis (median=0.06, p<0.0001), and relapse (median=0.001, p<0.0001) phases, compared to the control group (median=0.08). FOXP1 gene expression on the 15th day of the treatment was significantly higher than its level at the new diagnosis stage (p<0.001). Moreover, FOXP1 gene was significantly downregulated in the relapse phase compared to the new diagnosis. Patients whose number of bone marrow blasts on the 15th day of the treatment was below 5% had higher FOXP1 gene expression at the diagnosis phase (Spearman’s correlation, P<0.05, r=-0.485) and higher ratio of diagnosis/day 15 (p<0.001, Mann-Whitney U test). Conclusions: FOXP1 levels could be a potential biomarker of therapy response in remission induction therapy for pediatric BCP-ALL patients.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4879-4879
Author(s):  
Marinella Veltroni ◽  
Maddalena Paganin ◽  
Chiara Frasson ◽  
Giulia Fabbri ◽  
Antonio Marzollo ◽  
...  

Abstract Recent studies suggest that the majority of malignant cells found in B-cell precursor acute lymphoblastic leukemia (BCP-ALL) arise from a rare population of leukemic progenitors. Little information is available on the presence of clonal rearrangements in cells at the stage of early precursor. To address this issue we analyzed clonality profile of early leukemic precursors sorted by flow-cytometry. Leukemic cells were obtained from bone marrow samples collected at diagnosis from 6 patients with childhood BCP-ALL. Furthermore, bone marrow cells were collected from 3 healthy children who were harvested for bone marrow donation. Three subpopulations of leukemic cells were investigated: total unsorted blasts, the sorted CD34+/CD38−/CD19+, and the sorted CD34+/CD38−/CD19− cells. Immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements were screened by polymerase chain reaction (PCR) in the sorted populations and in the bulk leukemic cells in order to identify molecular markers of clonal evolution. Sequence analysis was then performed on the N-region. Overall, a total of 38 different Ig/TCR gene rearrangements were identified in the 3 cell populations under study (total blasts, CD34+/CD38−/CD19+, and CD34+/CD38−/CD19−). Of them, 13 (34%) were found in the three populations; 12 (31%) were found in two of the three populations: 7 in total blasts and CD19+ subset, 3 in total blasts and CD19−, 2 in CD19− and CD19+; finally, 13 were found only in one subpopulation: 4 in total blast cell, 5 in CD19+, 4 in CD19−. In all the six patients studied, BCP-ALL progenitors CD34+/CD38−/CD19− and CD19+ and the bulk tumor blasts shared at least one Ig/TCR gene clonal rearrangement with the same N-region. In 5 out of 6 patients at least one rearrangement detected in the BCP-ALL progenitors was undetectable in total blasts. Conversely, in 3 patients the clonal rearrangement observed in the bulk leukemic cells was not identified in any of the two sorted ALL precursor populations. Clonal rearrangement was never detected in the samples from healthy bone marrow donors. Our findings confirm that clonal rearrangement may be detected at the stage of early B-lineage precursor CD34+/CD38−/CD19−, suggesting that leukemic transformation may occur at this stage or even before in BCP-ALL. We plan to extend this observation by repopulating studies in NOD/SCID mice.


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